Electrical resistivity of K3C60.

We have measured the electrical resistivity p of K 3 C 60 prepared in a pressed pellet form, by employing a contactless technique operating at microwave frequency (60 GHz). The temperature dependence of p can be fit by the functional form ρ(T)=a+bT 2 and the magnitude of the resistivity at T c , ρ(20 K), is on the order of 0.5 mΩ cm. We also find that the resistivity drops by almost an order of magnitude between 300 and 20 K